Amplifier input impedance question

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When i'm using my DB, I use my usual electric bass gigging rig (Genz STL 9.0 & Berg HD210). I use a Radial tonebone pz-pre which is a fantastic bit of kit. The input impedance is 10mohm. I'm looking for a smaller/quicker set up for rehearsals & quieter gigs so i'm considering buying a combo. I want plenty of headroom and a decent volume should it be required. One of the combo's I've been looking at which seems to be suitable for DB has a 1mohm input (GK MB112). Question is, will I notice a difference if I go direct to the amp? Also some of the AER combo's are rated at 1mohm. Thanks in advance.

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Does a combo exist which has an input impedance of more than 1MOhm? If not, either you will be happy going straight in, or you will have to bring your Tonebone.

The reason I ask is that I could consider purchasing ANY combo if i'm going to have to use the tonebone to get an acceptable sound. If I purchase a combo that is more specific to the DB, then this limits the options and could increase the outlay (significantly in some cases). If I go down this route, one possible advantage is not to have to use the tonebone. In fact, this could be sold and the money used to add to the cost of a more expensive DB friendly amp. If I buy a DB friendly amp and it doesn't sound as nice plugging straight in as with the tonebone, then I could have settled for a less costly standard combo. I believe the Phil Jones combos have a 4.7mohm input however I believe that the smaller combos are not that loud.

So, if anyone has a pz-pre (or a 10mohm preamp pedal) and an amp with a 1mohm input, have you A/B tested both and was there a noticeable difference?

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That depends on the pickup you use. 1Mohm isn't that sensitive. Most small combos are suited for electric bass, so I solved the issue by putting a Creation AudioLabs Redeemer Circuit in between, the belt pack. It is a small buffer, originally made for electric basses or use of long cables, but works very well with my Realist Lifeline. It has an input impedance of more than 20 Mohm, so you can use ANY amp. https://www.creationaudiolabs.com/redeemer

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That depends on the pickup you use. 1Mohm isn't that sensitive. Most small combos are suited for electric bass, so I solved the issue by putting a Creation AudioLabs Redeemer Circuit in between, the belt pack. It is a small buffer, originally made for electric basses or use of long cables, but works very well with my Realist Lifeline. It has an input impedance of more than 20 Mohm, so you can use ANY amp. https://www.creationaudiolabs.com/redeemer

Interesting.....! Thanks for sharing this. I think the belt pack would suit my needs very well.

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Does a combo exist which has an input impedance of more than 1MOhm? If not, either you will be happy going straight in, or you will have to bring your Tonebone.

I have a Phil Jones Bass Briefcase which is listed as > 4MOhm for the passive input, and it still sounds a hell of a lot better with my EDB-1 in front of it. Not sure if this is due to the EDB-1 impedance or other factors.

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I have a Phil Jones Bass Briefcase which is listed as > 4MOhm for the passive input, and it still sounds a hell of a lot better with my EDB-1 in front of it. Not sure if this is due to the EDB-1 impedance or other factors.

I had the PJB Double Four, but the preamp SUCKED. I got that "digital feel" from it...

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I use an Orchid Electronics active DI/mute pedal. It’s got a simple good buffer preamp, so helps piezo pickups sound a bit fuller, plus the mute switch is very handy. I’ve used it for years, in front of many combos by GK/SWR etc etc.

Many years ago I was talking to Jon (Orchid’s designer/maker) about high input impedance, and he thought the benefits of going very high (over 3M?) were minimal, and usually just started to add more potential for noise problems.

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My pjb combo (4Meg Ohm input) is fine with a double bass without any pre-amp ... but I guess it's dependent on the pickup ( mines a realist sound clamp). the bass Tutor at our local jazz sessions uses a markbass mini ( only 500kOhm) with a realist copperhead pickup and no pre .. also sounds great.